Apparatus for monitoring nutrition, especially fermentation in the rumen of a ruminant

ABSTRACT

An apparatus for monitoring nutrition, especially fermentation in a rumen of a ruminant, is designed to be orally applied to the ruminant and to stay permanently in the rumen. The apparatus includes: a) at least one sensing unit for sensing a characteristic value of dissolved carbon dioxide in the liquor of rumen and/or reticulum; and b) at least one first communication unit for the wireless communication of data with a respective second communication unit outside the ruminant. The sensing unit includes at least one attenuated total reflectance (ATR) sensor.

INTRODUCTION

This disclosure relates to an apparatus for monitoring nutrition,especially fermentation in the rumen of a ruminant like a cow, a goat, asheep and the like.

Ruminants are in many countries of the world used to produce milk and/orto produce meat. Both the milk and the meat production per ruminant haveincreased significantly over the last decades. Responsible for this riseis on one hand the genetic improvement of the ruminants e.g. bybreeding, and on the other hand a better understanding of thenutritional requirements of the cattle.

In particular, in larger herds of dairy cattle the feed management ofthe herd frequently needs optimization. In particular, acidosis shall beavoided. Ruminal acidosis is understood as an increase in acidity in therumen and described as a decline of the pH of the rumen content for aperiod of time which is enough to have physiological consequents on theanimal affected by it. In that regards, metabolic and respiratoryacidosis is understood as the increase in acidity of the blood and othertissues. In ruminants metabolic and respiratory acidosis is stronglycoupled to the decline in rumen pH. Therefore, attempts were made tomeasure the rumen pH value in situ.

Prior art describes a bolus with an included pH meter and a temperaturesensor e.g. in GB 2 455 700 A. This pH sensor functionselectrochemically, i.e. it uses a pH electrode for measuring the pHvalue. Such a system is disadvantageous, as the used sensor driftsalready after some weeks of use in the rumen.

Nevertheless, research and documentations demonstrated that nutritionaldiseases in ruminants were in fact caused by the accumulation of rumendissolved carbon dioxide and not to the concomitant decline in rumen pH(Laporte-Uribe, 2016, 2019).

Dissolved carbon dioxide is a molecule of carbon dioxide associated to amolecule of water (hydronium). In other words, dissolved carbon dioxideis the liquid form of carbon dioxide when in contact with water.Dissolved carbon dioxide is linked to the main rumen buffer system andits decline or increase during fermentation influence the final rumenpH.

Normally, rumen dissolved carbon dioxide accumulation is limited,because standard physicochemical properties of the rumen fluid promotethe carbon dioxide removal via eructation. However, modern feeding dietsare high in energy which affect viscosity of the rumen liquid. Thesediets also have small particle sizes (physically effective fiber) whichreduce surface tension and reduce chewing and saliva secretion limitingbuffer addition into the rumen digesta. The changes in physicochemicalproperties promoted by these diets, i.e. changes in viscosity andsurface tension, might prevent the release of dissolved carbon dioxidefrom the rumen liquid. Due to the normal chemical equilibrium betweencarbon species, some of this dissolved carbon dioxide is transformedinto bicarbonate, and thus, CO2 is “holdup” or retained within thedigesta. This same phenomenon will create an even larger postprandialdissolved carbon dioxide concentration in the rumen. For instance,fermentation after feeding leads to rumen pH decline and the holdupbicarbonate will be quickly transformed into dissolved carbon dioxide.Moreover, and due to the increase rumen liquor viscosity, the excess ofdissolved carbon dioxide will be only slowly released, and itaccumulates at high concentrations for extended periods of time. Theincrease in dissolved carbon dioxide affects rumen microorganisms andtheir product of fermentation the volatile fatty acids (the energysources for ruminants). It also increases carbon dioxide absorptionthrough the rumen wall, as dissolved carbon dioxide can diffuse almostfreely into the body. The excess of carbon dioxide produces conditionsof cellular hypercapnia and hypoxia that will lead to respiratory andmetabolic acidosis and the onset of nutritional diseases in ruminants.Therefore, it is the rise in dissolved carbon dioxide and not theconcomitant decline in rumen pH that trigger these diseases.

Therefore, monitoring the concentration of dissolved carbon dioxide inthe rumen can be used to predict, prevent and control the onset of rumenacidosis, subacute rumen acidosis, metabolic and respiratory acidosis,bloat, abomasal dysplasia, low milk fat syndrome and other nutritionalsyndromes and diseases associated to carbon dioxide holdup and/or foamformation in the gastrointestinal tract of ruminants.

On the other hand, the rise of rumen dissolved carbon dioxide duringnormal conditions produces a physiological response in the rumenepithelia that stimulate nutrient uptake and enhances milk productivity.In simple terms, dissolved carbon dioxide provides a signal for nutrientavailability and the body reacts by absorbing more energy; this effectleads to greater milk productivity (Laporte-Uribe, 2019). Thus,monitoring dissolved carbon dioxide in vivo is advantageous in bothways: a way to avoid the onset of nutritional diseases and a way topromote better and more efficient rumen fermentation (Laporte-Uribe,2019).

WO 2015/121220 describes a method and an apparatus for monitoringnutrition, especially fermentation in the rumen of ruminants, whereinthe concentration of dissolved carbon dioxide is measured. The apparatuscomprises a sensor having a measurement chamber into which the dissolvedcarbon dioxide can diffuse, and the concentration of dissolved carbondioxide can be indirectly estimated, e. g. through apolytetrafluorethylene (PTFE) membrane. However, this methodology relyon the constant flux of carbon dioxide thorough the membrane and dietarychanges might modify rumen physiochemical properties which also affectgas influx through the PTFE membrane. Thus, the amount of dissolvedcarbon dioxide by this method might be underestimated.

SUMMARY

An object of the present disclosure, per an embodiment, is to provide animproved apparatus for monitoring nutrition, especially fermentation inthe rumen of ruminants, which eliminate the need for gas migration,reducing the effect of changes in physicochemical properties and candirectly monitor dissolved carbon dioxide concentrations. Thisdisclosure also suggests a methodology to use the information providedby the sensor or array of sensors to optimize milk productivity orprevent nutritional diseases in an individual basis, feeding groups orthe whole herd of ruminants.

According to an aspect of the disclosure, per an embodiment, anapparatus for monitoring nutrition, especially fermentation in a rumenof a ruminant, wherein the apparatus is designed to be orally applied tothe ruminant and to stay permanently and in direct contact with therumen liquid, is proposed, comprising at least the following units:

a) at least one sensing unit for sensing a characteristic value ofdissolved carbon dioxide in the rumen liquid and/or reticulum; and

b) at least one first communication unit for the wireless communicationof data with a respective second communication unit outside theruminant, wherein the sensing unit includes at least one attenuatedtotal reflectance (ATR) sensor.

c) a hermetic casing that provides protection from the outsideenvironment.

d) An interphase that provide insight on the health and nutrition of anindividual ruminant or a group (herd) of ruminants.

In particular, an aspect of the present disclosure, per an embodiment,is an apparatus for monitoring nutrition, especially fermentation in arumen or in a reticulum of a ruminant, wherein the apparatus is designedto be orally applied to the ruminant and/or reticulum and to staypermanently and in direct contact with the rumen and/or reticulumliquid, wherein the apparatus comprises at least the following units:

a) at least one sensing unit for sensing a characteristic value ofdissolved carbon dioxide in the liquor of rumen and/or reticulum; and

b) at least one first communication unit for the wireless communicationof data with a respective second communication unit outside theruminant,

wherein the sensing unit includes at least one attenuated totalreflectance (ATR) sensor,

wherein the sensing unit further comprises a light source emittinglight, wherein a light channel is provided that leads light generated bythe light source into a prism of the attenuated total reflectancesensor, said prism having a higher refractive index than rumen liquidand/or reticulum liquid, wherein the prism of the sensor is capable ofbeing in direct contact with the rumen liquid and/or reticulum liquid,and

wherein the apparatus comprises a hermetic casing that providesprotection from the outside environment.

Accordingly, an aspect of the present disclosure, per an embodiment, isa use of an apparatus for sensing a characteristic value of dissolvedcarbon dioxide in the liquor of rumen and/or reticulum, for monitoringnutrition, especially fermentation in a rumen of a ruminant, wherein theapparatus is designed to be orally applied to the ruminant and to staypermanently in the rumen and wherein the apparatus is like definedabove.

The disclosure, per an embodiment, is based on attenuated totalreflectance (ATR) spectroscopy especially on an infrared sensor usingattenuated total reflectance as sampling technique.

The ATR sensor uses the phenomenon of total internal reflection. A beamof radiation passes through a prism and undergoes total internalreflection through the prism. A so-called evanescent wave is created.The evanescent wave protrudes only a few micros beyond the prismsurface. The distance that the evanescent wave extends from the prismsurface depends upon the material of the prism and the intensity of thelight emitted. The prism of the sensor is in a direct contact with therumen liquid and/or reticulum liquid. In contrast to the prior artsensors there is no need for carbon dioxide to migrate into a samplingchamber, thus giving a direct and more accurate determination of thedissolved carbon dioxide concentration in the rumen and/or reticulumliquid.

According to the disclosure, per an embodiment, the ATR sensor comprisesof a prism. Prism in the meaning of the disclosure is not restricted toa special geometry. Prism in the meaning of the disclosure is an opticalelement which meets the requirements of an attenuated total reflectance.In other words, the prism in an embodiment has a higher refractive indexthan the sample. It is preferred, per an embodiment, a low-cost siliconATR prism, cut as a trapezoid or rectangle (see figure). One side of theprism is in direct contact with the rumen fluid (sampling side). Thetotal area of the prism exposed to the rumen liquid will be smaller thanthe size of the prism. This small surface on the sampling side can beachieved by using the cap of the bolus (cylinder) as a filter and coverof the channel, e.g. a rectangular opening on the stainless-steel cap,FIG. 1 . The borders of the opening in the cap are angled to improvelight scattering and reduce fouling. This configuration allows the lightto generate large number of internal diffractions, whereas the smallsampling area is designed to maximize light scattering and samplepenetration. However, other configurations can be explored. The interiorof the sensor's cap, that covers the prism, has an aluminum frame wherethe prism is inserted. It is sputtered with a refracting metal toachieve good refraction and avoid interference. Silicon sealing agent isspread in the cap to seal the borders of the sensor from environment.The prism is kept in place by pressure against the borders and the angleof the channel; the cap folds into the body of the stainless-steelcasing by pressure. For this a male and female corrugated siliconstopper, a series of silicon O-ring and a silicon sealant agent arecombined during assembling to hermetically close the junction.

The sensing unit comprises of a light source emitting infrared light.The preferable light source, per an embodiment, is a low poweredinfrared light emitting diode (IR-LED). These types of IR LED lightsnormally are used for CO2 sensing (4228 nm) with a wavelength range from3500 to 5000 nm and a spectral width of 500 nm, however fewmodifications are necessary for dCO2 detection (4268 nm). As follows:

An essential part of the sensing unit designed, per an embodiment, is alight channel that leads the IR light generated by the IR-LED into theATR prism. It also avoids that the photodiode detector, in the otherside of the channel, capture the light emitted by the IR-LED before isdiffracted into the ATR prism. The preferable material, per anembodiment, for the channel is high grade aluminum; however othermaterial can be explored. The best configuration is an inverted U-shapedchannel where the IR-LED light is placed in one of the tips of theU-shaped. The interior surface of the channel is sputtered with a highlyrefracting metal, e.g. aluminum or gold alloys, to ensure optimal lighttransmission into and out of the ATR prism. The shape of the channel isrectangular or circular. Most of the channel is covered by a thin sheetof aluminum, except for the base where the ATR prism is placed. Bothends of the channel are bent or curved to achieve: high diffraction ofthe scattered light, the optimal light incidence angle into the ATRprism and the optimal penetration of the IR-LED light into the sample.Those conditions provide greater advantages on signal repeatability anddCO2 detection, according to certain embodiments. However, other shapesand configurations might be explored depending on the best setup fordiffraction, refraction and penetration into the sample.

In the other end of the sensing unit's channel, the photodiode detector(PD) is placed. The PD collects the light scattered in the diffractionprocess by the prims. The intensity of the attenuated light signaldetected by the PD is inversely proportional to the rumen dCO2concentration by the integration of the light within a narrow wavelengthaccording to the Beer-Lambert law and equation.

One of the main issues of adapting this CO2 sensor to dCO2 measurementis a strong interferes with water (IR peak at 4700 nm). It is known inthe literature that the CO2 sensors can be modified to achieve anarrower wavelength separation from, i.e. 600 nm to 100 nm, but thissolution required greater power consumption, thus not suitable forwireless applications. A different solution is proposed that comprise touse another low powered IR-LED light and PD to target water at adifferent IR wavelength 1800-1950 nm and use this output to create abaseline for water content of the fluid. Thus, the dCO2 concentrationcan be subtracted from the differences between the water background anddCO2 signal. Alternatively, the water content of the rumen fluid isrelatively constant (3 to 4% Dry Matter), and during calibration, thesensor output might be corrected by this effect. Nevertheless, thepreferred process, per certain embodiments, will be defined according tothe cost of development vs the accuracy of the measurement and theefficiency on the detection method.

An important feature of this sensor, per an embodiment, is the capacityof self-calibration, as rumen boluses are not retrievable. Because ofthe almost constant water content, the use water as a reference signalprovides also the opportunity to use its background noise to account forthe decline in performance overtime of the sensor (drift) and correctthe dCO2 signal using standard algorithms. Measurements of water doesnot require continuous measurement, as the detection of dCO2 requires,only few recordings per day e.g. 24 times/day might be enough tooptimize dCO2 estimations and the self-calibration process. Similarly, adaily average per feeding group or the herd average can be used toimprove dCO2 detection, a process that can be done internally within theboluses (i.e. sending an average value from the receiver's CPU (controlprocessing unit) back into the bolus for self-calibration) or externallyafter the data has been transferred and analyzed.

Another strategy to improved reliability and the strength of thescattered signal to optimize dCO2 determinations is to have a smalldiffraction surface area to increase the repeatability of the results.Algorithms have been also developed to improved dCO2 determinationsusing this effect. It was also proposed the use of a low power lock-inamplifier (LIA) to improve the signal to noise ratio by phase sensitivedetection. In other words, identifying a specific reference frequencyand phase within the variable input and amplifying that signal.

Another important feature, per an embodiment, of this bolus foroptimizing dCO2 monitoring is the inclusion of a low power microtemperature sensor in contact with the stainless-steel casing to correctthe dCO2 measurements by the ambient temperature (rumen or reticulumtemperature). The temperature sensor also provides information aboutcore body temperature of cattle. This information can be used to detectillness and monitor ruminants' health, improving nutritional diseasedetection.

The sensing unit also comprises of an energy harvester used to increasethe battery lifetime by harvesting the small energy generated by rumenperistaltic movements and cattle motion. The raw signal from theaccelerometer can be also used to monitor the health status (i.e. heatdetection and lameness and other metrics) and provide further signalsand alarms to the farmers.

All the sensors within the rumen bolus: dCO2, water, temperature and theaccelerometer are controlled by a microcontroller unit (MCU). Itcontrols also the storage and the wireless two-way communication withthe receiver PCU placed in the ham and milking parlor. Themicrocontroller also monitors the battery life and charge.

It adjusts updates and controls different algorithms stored in thefirmware. The MCU of the system also controls and monitors the two-waycommunication with the external receiver. For this the MCU includes alow power wireless transceiver and an antennae. The frequency oftransmission depends on the defined network system, e.g. it couldinclude sub GHZ 863/928 MHz or Lora 433/868/915 MHz. Both networksystems provide good two-way communication in the rumen environment andtransmission distances of 500 m radius. These distances provide coveragefor most of barns and dairy sheds in the market. For most applicationsthe signal transmission rate can be setup to Live date transmissionevery 15 min, 2 h or every milking (2-3 times per day).

In any case, the MCU also is equipped with a microSD-memory card. Thetotal size of the memory is enough to organized, compress and store theinformation recorded every 15 sec until the receiver actively ask forthe information to be transmitted from each unit. A positive signal ofcomplete transmission from the receiver to the boluses mightautomatically erase the information stored; otherwise the informationmight remain in the bolus SD-card for another cycle, if the transmissionwas not completed. Another important aspect of the two-way communicationbetween the rumen boluses and the external receiver, per an embodiment,is to maintain and update time synchronization and firmware update.

The network of rumen boluses can be integrated and coordinated by thereceiver that acts as an RF unit providing two-way communication. Aseries of algorithms provide the PCU of the receiver with the capacityto synchronize and crosstalk with large number of units (up to 5000units/herds). The receiver also connects directly with cloud baseservers to update software and firmware, and upload information tomonitor the equipment performance. A large virtual and physical memoryallowed the PCU to calculate the sensor information and store theinformation of many devices for a period of 1 month. Daily reporting ofthe nutritional performance of the individual cattle, feeding groups andherd on farm can be created and displayed on the user interphase. Theinformation is processed within the PCU of the receiver or throughcloud-based services. The information will be used to benchmark the farmand for future veterinary diagnostics. Alert are generated forindividual or groups or herds at risk of nutritional diseases. Theinformation also is used to provide nutritional advice about thequantity and quality of the dietary treatments, improving the feedefficiency, i.e. increasing milk productivity by kilogram of feed.

A lithium-based battery provides the energy for the optimal performanceof the rumen boluses. The final dimensions and characteristics depend onthe maximum requirement to sustain the correct function of the sensorsand components (LIA, MGU and RF units) for a period of at least 2 years,or for the production lifetime of the ruminant (˜7 years). The mainrestrain on battery size and capacity is the size of the rumen bolusallocated to the ruminant.

The apparatus forms a so-called bolus and the monitoring takes placewithin the rumen, reticulum and/or the ventral sac liquor. A medicalgrade stainless steel casing and the specific gravity (>2.3 g/cm3) ofthe device from the rumen bolus within the rumen or reticulum liquid.Keeping the dCO2 sensor under the rumen fluid is important to reduceinterference with gas CO2 present in the gas phase (cap), in the top ofthe dorsal sac of the rumen. The CO2 might interfere with the dCO2determination if the rumen bolus is exposed to the gas cap (IR 4228 nm).

The dimensions of the bolus may also be important. It should be nolonger than 150 mm and 30 cm diameter for large ruminant such as cattleand buffaloes and 100 mm and 18 mm diameter for small ruminants likesheep and goats. Silicon O-rings or other types of sealant agents willbe used to hermetically seal the electrical components from thesurrounded rumen liquid. This feature provides protection from thesurrounding liquid. Rumen substance migration normally limited theoperational life of rumen boluses i.e. rumen pH boluses. The pH sensoris open to the rumen environment and rumen substances can migrate intothe electronics, reducing the life time of the sensors and destroyingthe electronics. Moreover, rumen pH devices can be harmful forruminants, as heave metals and other substances use on these devices canleak back into the rumen fluid contaminating the rumen fluid. Thehermetic casing proposed for our sensor solved these issues and improveoperational lifetime.

It is preferred, per an embodiment, to monitor the concentration ofdissolved carbon dioxide at discrete point of times, preferably inintervals of less than one minute. Nevertheless, it is possible tochange this time interval, in particular based on pre-determinedcircumstances, e. g. for some time after feeding. This can be triggeredby an outside signal, e. g. from a communication unit combined with thefeeding equipment or the like.

Furthermore, the gathered data can be used to generate informationregarding the efficiency of fermentation in the rumen and the risk ofnutritional diseases, including syndromes and diseases such assubclinical acidosis, acute acidosis, bloat, abomasal dysplasia, ketosisand others. This analysis can either be performed in an analysis unit inthe apparatus or outside, after transmission via a first communicationunit inside the rumen and a second communication unit being situatedoutside the animal. By this it is possible to generate specific warningsignals for the farmer if specific criteria, like e. g. high dCO2concentrations for 3, 5 or 12 h day.

Other features which are considered as characteristic for the disclosureare set forth in the appended claims, noting that the features presentedindividually in the claims can be combined in any technologicallymeaningful way and give rise to additional embodiments of thedisclosure.

We described the use of dissolved carbon dioxide (dCO2) in the rumen ofcattle to monitor and prevent nutritional diseases. In brief, thedissolved carbon dioxide (dCO2) holdup, in the rumen liquor due tophysicochemical changes and fast fermentation of nutrients might explainmany of the nutritional diseases and syndromes that are endemic of dairyfarming. As a matter of example:

Rumen Acidosis and The dissolved carbon dioxide (dCO2) accumulation dueSubacute Rumen Acidosis to physicochemical changes in the rumen liquorwill trigger (SARA): rumen acidosis by reducing bacterial activity,decline of feed intake and nutrient digestion, prolonged period of highdissolved carbon dioxide (dCO2) concentrations will modify the acid-basebalance of the rumen epithelia and increase in CO2 diffusion into theblood-stream will results in the establishment of metabolic andrespiratory acidosis in cattle.

Abomasal dysplasia: The outflow of dCO2 saturated rumen liquor into theabomasum (true stomach) will mean that large amount CO2 and CH4 can bereleased in the abomasum after acid digestion, which will displace theabomasum to abnormal anatomical locations in the abdominal cavity,condition that has to be surgically corrected.

Bloat: The formation of stable foam in the rumen is a consequence andmanifestation of the dissolved carbon dioxide (dCO2) holdup due to pHphysicochemical changes of the rumen liquor during fermentation. Foamformation and stabilization in the rumen will inhibit eructation andanimals will become tympanic. The condition, if severe, will lead todeath of cattle.

Ketosis: The dissolved carbon dioxide (dCO2) holdup in the rumen willgenerate satiety signals that will limit feed intake, the reduction innutrients intake will trigger fat mobilization and ketone bodyproduction, condition known as ketosis.

Low fat syndrome: The decline in acetic acid in favour of propionic acidproduction in the rumen will trigger the decline in fat content of themilk. High dissolved carbon dioxide (dCO2) concentrations in the rumen,on one hand stimulate the growth of bacteria that produce large amountof propionic acid. On the other hand acetogenic bacteria will favourother metabolic pathways reducing acetic acid production.

The apparatus, particular a wireless nutrition device can monitor theconcentration and evolution of dissolved carbon dioxide (dCO2) in therumen. The knowledge of threshold associated to the presentations ofthese diseases will allow farmers, nutritionist and consultants todesign diets that promote better rumen fermentation and reduce theprevalence of nutritional diseases on farm.

The disclosure will help nutritionist and farmers to directly monitorrumen fermentation and will give a first account on feed quality,feeding management and animal performance by optimizing rumen bacterialgrowth. Farmers will be able to feed diets that provide the rightbalance of nutrient and feeding ruminant at the right time during theday to optimize feed conversion efficiency and milk production.

Fermentation monitoring is achieved by measuring the changes andevolution dissolved carbon dioxide (dCO2) concentration in the rumenliquor. Bacteria growth and metabolism are affecting by the changes inrumen dCO2 concentrations (Laporte-Uribe, 2016). Therefore,post-prandial changes and evolution of dissolved carbon dioxide (dCO2)concentrations might follow bacterial growth and monitoring dissolvedcarbon dioxide (dCO2) concentrations with an indwelling rumen bolus canprovide an accurate measurement of bacterial fermentation.

The real-time monitoring of bacterial fermentation provides anopportunity to influence, particularly to optimize bacterial growth, forinstance by reducing the time between lag phase and exponential growth,or by identifying when stationary growth phase begins, and/or byavoiding that rumen fermentation reaches decline phase of growth. Inother words, the synchronization of growth cycles will improve theutilization of nutrient and overall production of by-products.Ultimately, most of the by-products of rumen bacterial growth are usedas a source of energy for milk production; similarly, most of theprotein in milk of dairy cattle comes from the digestion of rumenbacterial cells. Therefore, optimal rumen bacteria growth will mean alsooptimal energy and protein availability for milk production.

The identification and automatic warnings of bacterial growth andmetabolism in the rumen can be used by farmers, nutritionist andconsultants to improve feeding management routines. For instance, theaddition of feed (feeding) at specific times of the day when the lack ofnutrients reduce fermentation and bacterial growth might lead toincrease feed efficiency conversion and nutrient uptake. Moreover,adjusting feeding management practices e.g. feeding time, will improvesnutrient output by synchronizing and enhancing bacterial growth. Thesynchronization of nutrient supply with bacterial growth in the rumenalso has been shown to improve feed intake, feed conversion efficiency,and milk production in dairy cattle.

Another relevant application could be the use of warning signals due tochanges in bacterial growth to activate automatic feeding equipment(feeder and push-ups robots) to deliver feed to a specific animal,feeding group or herd. This can be achieved by transmitting theinformation obtained from the rumen of animals or group of cows equippedwith the system, in real-time, to a central processing system that willcontrol and activate the equipment to deliver feed. For that, the systemwill be designed to transmit the information, while the animal is beenmilked or emitting the information to receivers conveniently allocatedaround the ham, i.e. in the feeding area.

On the other hand, by analyzing dissolved carbon dioxide (dCO2) datatransmitted wirelessly from single individual animal, feeding group orherd, the best daily routine of feeding for that particular individualor set of animals can be established. These feeding routines can beadjusted, after few hours of data processing, if changes in diet orcomponent occurs, such as the opening of new batches of silage or theaddition of new feed components. With this information an optimal feedintake can be obtained and higher milk production with lower nutritionalproblems might be achieved.

Monitoring bacterial growth and fermentation using dissolved carbondioxide (dCO2) sensors becomes more important if we think on monitoringfeed quality and feed composition. The evaluation of feed digestibilityfor ruminants can be easily monitored using in vitro gas productionsystem; they provide an idea of the amount of fermentative materialpresent in the different components of a ruminant diet. These systemsare based on measuring the release of gas from the incubation ofnutrient in a sealed container which mimics the in vivo fermentation inthe rumen; CO2 is the main gas collected using this methodology. Dairycattle diets also are set according to the nutrient content of thedifferent components (evaluated separately); however the quality andquantity of nutrients on those components are highly variable on farm.Therefore, the mixing and a particular diet (with several components) donot warrant the provision of appropriated amount of nutrients for anadequate fermentation and milk production. This whole problem ofquantity and quality of the diet is worsening by cattle's habits of feedselection while feeding.

Indwelling dissolved carbon dioxide (dCO2) rumen bolus and real-timemonitoring of dissolved carbon dioxide (dCO2) evolution can be used aslive monitoring of the digestibility of ruminant diets in a similar wayas the in vitro system. The analysis of individual, feeding group andherd information will provide direct insight on the fermentative qualityof the feed given to those animals. Because the feed information comesfrom the true intake of cattle, the information will reflect better thetrue nutritional value of the ration provided to each individual cow andalso the whole herd.

For instance, a decline in the rumen exponential growth phase mightindicate that specific diets lack of some of the nutrient required foroptimal bacterial growth or if the stationary phase is reached fasterwith another diet, it might suggest that that particular diet is rich inhighly fermentative material but might lack of the right amount of fiberfor an adequate rumen fermentation. This information can be directlycorrelated to the milk yield for a single animal or group of cows (i.e.feeding group) and a clear idea of the nutrition value of a specificdiet for feeding cattle can be achieved.

In other words, the information collected from a large set of animalswithin the herd will help to evaluate the nutritional value of the feedgiven in that specific herd or feeding group. Algorithms can be createdto generate realtime warnings of the decline on feed quality or the lacknutrients that might limit optimal rumen fermentation (i.e. fibercontent of the diet) and milk production. Therefore, farmers,nutritionist and consultants will be able to quickly modified quantitiesand components to optimize rumen bacterial growth, increase milkproduction and reduce nutritional diseases. As above, the integrationwith automatic feeding systems will enable the optimization of diets ina day by day basis, enhancing milk production and reducing nutritionaldiseases on farm.

Changes and saturation of rumen liquor with dissolved carbon dioxide(dCO2) can limit or change bacterial growth, bacterial metabolism andby-products of biochemical reactions of bacteria. The real-timemonitoring dissolved carbon dioxide (dCO2) concentrations will enable toidentify when different thresholds are reached and different biochemicalpathway might be activated, which might alter the endproducts of thatreactions. In similar way high dissolved carbon dioxide (dCO2)concentrations might shift bacteria populations in the rumen to groupsthat are better adapted to those environmental conditions; thosebacteria might produce different end-products which in turn might changethe overall concentration of nutrient in the rumen.

As an example and depending on other environmental conditions (mainlytemperature) the following threshold can be found in the rumen. Optimalbacterial growth required dissolved carbon dioxide (dCO2) concentrationsbetween ˜12 mM and ˜20 mM, on those conditions the main product offermentation is acetic acid, higher concentrations (greater than 20 mM)might enhance propionic acid concentrations (˜60 mM is optimal for largeproduction of propionic acid in batch systems) and the increase inlactic acid production (˜120 mM) might be seen due to excessivedissolved carbon dioxide (dCO2) accumulation.

Monitoring of dissolved carbon dioxide (dCO2) concentration in the rumenliquor will help farmers, nutritionist and consultants, not only toidentify risk health factors such as excessive accumulation of lacticacid and propionic acid, but also to optimise propionic acid (mainenergy source for cattle and for milk protein production) and aceticacid production (milk fat production) to provide optimal milk quality(optimal milk protein/fat ratio). With this tool farmers, nutritionistand consultants might be able to design diets that promote better rumenfermentation for optimal milk quality production and might reduce riskfactors associated to nutritional diseases. Algorithms will be designedto monitor in real-time dissolved carbon dioxide (dCO2) concentrationproviding relationship between short chain fatty acid concentrations(propionic, acetic, butyric and lactic acid) and thresholds will beestablished to correlate these important nutritional factors with milkquality.

Methane (CH4) is a waste product of fermentation and one of the maingreenhouse gases in the atmosphere, by monitoring the methaneconcentrations during fermentation a good indication of amount ofmethane been produced by a specific animals and/or diet might beobtained. The dissolved CH4 concentrations can be measured directly witha specific NIRS sensor for methane and the evolution of methane duringthe day will give a good indication of the amount of CH4 produce for acertain animal, group of animals and diets.

The combination of methane sensor information with milk yield data perindividual animals, feeding groups or herds will provide nutritionistand farmers with the possibility to adapt diets and minimize methaneemissions. By feeding diets that can achieved a reduction in methaneproduction during fermentation farmers could obtain higher feedconversion efficiency (more milk been produced per kg of feed given), orthe selection of animals that digest diets with higher conversionefficiency (producing more nutrients and less methane).

An indirect approach for measuring conversion efficiency and methaneemissions is by instead measuring dissolved carbon dioxide (dCO2)concentrations. There is a direct relationship between CO2 and CH4production in the rumen; Methanogens bacteria produce CH4 by reducing H2and CO2, this process is optimal at lower dissolved carbon dioxide(dCO2) concentrations (<60 mM) whereas higher dissolved carbon dioxide(dCO2) concentrations will tend to reduce CH4 formation, as othermetabolic pathways for energy production might be favour, and/or otherbacteria populations better adapted to thrive in high CO2 conditionsreplace Methanogens. Therefore, cataloguing animals between high and lowdissolved carbon dioxide (dCO2) producer might find that animals withhigher dissolved carbon dioxide (dCO2) concentrations or daily evolutiontend to produce less methane and convert feed more efficiently than lowdissolved carbon dioxide (dCO2) emitters.

In a similar way, bacterial populations in the rumen are unique and verystable for each individual animal, herd or group of animals.Establishment and maintenance of a particular bacterial populationdepends on the diet that animals received, but also on the internalenvironmental conditions of the rumen, most remarkably dissolved carbondioxide (dCO2) concentration. Hence, fermentation characteristicmeasured by monitoring dissolved carbon dioxide (dCO2) concentrationsand evolution will indicate which animals are more efficient intomaintaining a large biomass of bacteria that are capable to digestnutrients more efficiently (less waste in the form of CH4). Therelationship between dissolved carbon dioxide (dCO2) evolution and milkproduction of the animal might be a direct method to estimatefermentative efficiency and an indirect method to determine high methaneemitters.

Algorithms and equations will be created to show, in a clear andconsistent way, differences between and within animals, groups andherds. Similarly, methane production can be monitored externally andvalues correlated to dissolved carbon dioxide (dCO2) concentration andevolution measured directly. By combining CH4 emissions (real orestimated), dissolved carbon dioxide (dCO2) evolution and individualmilk information, we can have a close approximation on the feedconversion efficiency and methane emissions. The information can be usedby breeders, nutritionist, farmers and consultants to select moreefficient animals (higher conversion feed efficiency, less methane (CH4)emissions), similarly the information might be used to select the mostefficient diets or nutrients to minimize energy losses and CH4 emissionsin a group or herd basis (optimal feed conversion efficiency for milkproduction).

Although the disclosure is illustrated and described herein as embodiedin an apparatus for monitoring nutrition, especially fermentation in arumen of a ruminant, it is nevertheless not intended to be limited tothe details shown, since various modifications and structural changesmay be made therein without departing from the spirit of the disclosureand within the scope and range of equivalents of the claims.

BRIEF DESCRIPTION OF THE FIGURES

The subject matter of the disclosure, however, together with additionalobjects and advantages thereof will be best understood from thefollowing description of specific embodiments when read in connectionwith the accompanying drawings.

FIG. 1A-E shows an example of an apparatus

FIG. 2 shows the allocation of the equipment on the ham

FIG. 3 shows a scheme of how the information is processed

FIG. 4 describes how the results of that analysis are used to optimizefeed intake and reduce the risk of ruminal acidosis.

DETAILED DESCRIPTION

FIG. 1 shows an example of an apparatus 1 for monitoring nutrition,especially fermentation in a rumen of a ruminant, wherein acharacteristic value of dissolved carbon dioxide inside the rumen isdetermined. The ATR sensor unit 8 includes several sensors. The IR-ATRdCO2 sensor itself 4 contains an IR-LED light for dCO2 and water 3IR-LED light source. The light emitted by these sources is sent throughthe light channel 2 into the ATR prims 1 where the IR light iscompletely diffracted, a small amount of light in the evanescent wavepenetrates the rumen fluid in contact with the small window 20 in therumen bolus cap 21. The amount of light absorbed by the sample isdirectly dependent on the dCO2 and water concentrations. The remainingattenuated IR light travels throughout the channel 7 into the Photodiodedetectors 6 where the attenuated signal for dCO2 and water is sensed.The sensor unit 8 also comprises of a temperature sensor 5 and an energyharvester accelerometer, 9. The sensor unit is connected with themainboard 16 by an electrical connector, i.e. pin headers 10. Theinformation from the IR-ATR sensor is sent into the low power lock-inamplifier or LIA 12 which amplified the IR signal improving dCO2detection. The information is sent into the microcontroller unit, MCU13. The temperature 5, accelerometer 9, water and the dCO2 signals areprocessed within the MCU 13, compile and send it into the SD card memory14 for storage. The rumen bolus RF module 15 is in standby mode untilthe receiver 22 (see FIG. 2 ) provides the signal to transfer theinformation. The whole device is powered for a lithium based battery 17,kept in place by the holders 11. The stainless steel casing 18 providesa way to hermetically isolate the bolus from the rumen environment. Theplug in cap 21 is kept in place by a corrugated and rubber sealed maleconnector 19.

FIG. 2 shows how the receiver 22 gathers the information from theruminants in the barn. A network of antennas 26 allocated through theham or diary shed to provided the network for the two-way communicationbetween the receiver and the boluses RF module. The boluses transmit ofthe information and wait for positive confirmation from the receiver 22,once the receiver 22 confirm that the information has been appropriatelyreceived, the boluses returns to standby mode, the information stored inthe SD-card 14 can be deleted.

The units 23, 24, 25 can be applied to individual animals e.g. in riskof ruminal acidosis, to sentinel animals, e.g. animals per feeding groupor to the whole herd. The information stored in the boluses istransmitted at set intervals according to the protocols set in thereceiver 22 by the user. The receiver also acts as interface; in herethe information is further processed for optimization and to alsoinclude animals ID, date, feeding groups and other physiological andnutritional information per animal, herd and group. The receiver is indirect contact with the server 27 via internet and telephone services toprovide firmware updates, equipment diagnostic and big data analysis. Auser interface 28 might display the information analyzed in thereceiver's PCU and information from cloud services. The analysisdisplayed in the user interface 28, information might include: healthalarms, nutritional information for optimizing feed conversionefficiency and health status of cattle; see examples. The user interface28 might also be used by the farmers to enter specific nutritional andphysiological information, i.e. veterinary treatments, diet composition,etc., to improve the feedback and big data analysis.

FIG. 3 shows how the information gather from the rumen boluses can beused to monitor nutrition and cattle health. The advantages of thedisclosure are, per an embodiment, that an optimal rumen dCO2concentrations lead to better anaerobiosis, higher milk productivity andlower risk of nutritional disease, high dCO2 map or high dCO2. High riskof nutritional disease can be found in diets that produce Critical dCO2MAP, whereas Normal dCO2 MAP diets do not maximize feed conversionefficiency.

For instance, the boluses can be placed in the rumen of a sentinelcattle within feeding, all the animals in the herd, or risk cattle,prone to nutritional diseases. A receiver as a part of the secondcommunication unit controls a two way communication with the at leastone sensor, store data rom all sensing units and provide the data for afeeding management module.

A network of antennas that are conveniently deployed within a milkingparlour, milking stall establish two-way communications, betweenapparatuses and the receiver. A feeding management module processes theinformation and provides analysis and recommendations.

To reduce power consumption the apparatus is preferably in a “hearingmode” stand by and is activated on request. In a case that continuousmonitoring is preferred the apparatus records the information inpredeterminate time intervals, preferably every 15 seconds, and theinformation is compiled, stored and sent in predeterminate timeintervals, preferably every 10 minutes by the bolus. The receiverestablishes communication protocols with the bolus and the receivergives positive feedback to the boluses that information has beenreceived. In the case that a communication is not stablished, theinformation is stored in a data storage 14. which is a part of theapparatus until the next uplink.

Preferably the apparatuses 1 are asked to send information by thereceiver during milking session. Therefore, when cows enter the milkingplace and the receiver stablished communication with the apparatus, andthe apparatus send information. The receiver gives positive feedback tothe apparatus 1 that all information has been received. If acommunication is not stablished, the information is stored until thenext milking. The information achieved by the apparatus 1 is used formonitoring nutrition and to improve the animal health (see FIG. 3 ).

EXAMPLE

Rumen boluses are applied to the whole herd or sentinel animal withinfeeding groups. The information of the boluses is processed and rumenmaps suggest that feeding management provide low dCO2 concentrations(FIG. 4 ).

Diets are adapted by increasing starch, modifying the starch source andreducing the size of fiber on the total mix ration TMR. After furthermonitoring the sensors suggest that those modifications lead to the dietnow provides high rumen dCO2 concentrations FIG. 4 .

The dCO2 data might also suggest that the diet should be provided in 4feeding bouts throughout the day to increase dCO2 concentrations andavoid the rise of dCO2 to critical values (see FIGS. 4 ).

The data achieved by the boluses are also compared with the milk yieldto find the optimal output for that particular diet.

All the recommendations are recorded and provided in a daily report.

The information can be also given to an automatic feeding system whichuses the information to allocate feeding times and mixing conditions,preferably the type of components for example silage, hay and/orconcentrates, and particle size to provide optimal dCO2 concentrations.

All the features and advantages, including structural details, spatialarrangements and method steps, which follow from the claims, thedescription and the drawing can be fundamental to the invention both ontheir own and in different combinations. It is to be understood that theforegoing is a description of one or more preferred exemplaryembodiments of the invention. The invention is not limited to theparticular embodiment(s) disclosed herein, but rather is defined solelyby the claims below. Furthermore, the statements contained in theforegoing description relate to particular embodiments and are not to beconstrued as limitations on the scope of the invention or on thedefinition of terms used in the claims, except where a term or phrase isexpressly defined above. Various other embodiments and various changesand modifications to the disclosed embodiment(s) will become apparent tothose skilled in the art. All such other embodiments, changes, andmodifications are intended to come within the scope of the appendedclaims.

As used in this specification and claims, the terms “for example,” “forinstance,” “such as,” and “like,” and the verbs “comprising,” “having,”“including,” and their other verb forms, when used in conjunction with alisting of one or more components or other items, are each to beconstrued as open-ended, meaning that the listing is not to beconsidered as excluding other, additional components or items. Otherterms are to be construed using their broadest reasonable meaning unlessthey are used in a context that requires a different interpretation.

LIST OF REFERENCE NUMERALS

1 ATR prims

2 light channel

3 IR-LED light source

4 ATR sensor

5 temperature sensor

6 photodiode detector

7 light channel (attenuated light)

8 Sensor unit

9 Energy harvesters, Accelerometer

10 Electronic connector

11 Battery holders

12 lock-in amplifier (LIA)

13 microcontroller (MGU)

14 micro-SD card

15 RF unit

16 mainboard

17 Lithium based battery

18 Stainless steel easing

19 Male connector for the plug-in cap

20 ATR prims window

21 Plug-in cap

22 Receiver

23 sensor in individual ruminants

24 sensors in sentinel group

25 sensors in groups

26 Antennas in the milking parlor and ham

27 server

28 Software interfaces

1. Apparatus for monitoring nutrition and fermentation in a rumen of aruminant, wherein the apparatus is designed to be orally applied to theruminant and to stay permanently in the rumen, the apparatus comprisingat least the following units: a) at least one sensing unit for sensing acharacteristic value of dissolved carbon dioxide in liquor of rumen,reticulum, or both the rumen and reticulum; and b) at least one firstcommunication unit for wireless communication of data with a respectivesecond communication unit outside of the ruminant, wherein the at leastone sensing unit includes at least one attenuated total reflectance(ATR) sensor.
 2. Apparatus according to claim 1, wherein the apparatusis designed to remain permanently in direct contact with the rumenliquid, reticulum liquid, or both the rumen liquid and reticulum liquidand comprises c) a hermetic casing that provides protection from anoutside environment.
 3. Apparatus according to claim 1, wherein the ATRsensor comprises a prism with a higher refractive index than rumenliquid, reticulum liquid, or both rumen liquid and reticulum liquid andthe prism of the ATR sensor is designed to be in direct contact with therumen liquid, reticulum liquid, or both rumen liquid and reticulumliquid.
 4. Apparatus according to claim 1, wherein the ATR sensorcomprises a prism exposed directly to the liquid in the rumen orreticulum, wherein the prism is a silicone prism.
 5. Apparatus accordingto claim 1, wherein the at least one sensing unit comprises a lightsource emitting infrared light wherein the light source is an infraredlight emitting diode.
 6. Apparatus according to claim 5, wherein thelight source emits an infrared radiation with a wavelength rangingbetween 4.25 and 4.30 um.
 7. Apparatus according to claim 1, furthercomprising a temperature sensor for sensing the temperature in therumen.
 8. Apparatus according to claim 1, further comprising a casingmade at least in part from stainless steel and with a specific gravitygreater than 2.3 g/cm³ to keep the apparatus on the rumen and thereticulum liquid.
 9. Apparatus according to claim 1, wherein the atleast one sensing unit has the capacity of self-calibration. 10.Apparatus according to claim 1, wherein the at least one sensing unitcomprises a battery and an energy harvester used to increase batterylifetime by harvesting the energy generated by rumen peristalticmovements and cattle motion.
 11. Apparatus according to claim 1, whereinthe apparatus forms part of a network of rumen boluses.
 12. Milkingparlor, ham paddock or other type of ruminant housing structure andenclosure, comprising at least one second communication unit forwireless communication with a first communication unit in an apparatusaccording to claim
 1. 13. Apparatus for monitoring nutrition andfermentation in a rumen or in a reticulum of a ruminant, wherein theapparatus is designed to be orally applied to the ruminant, reticulum,or both the ruminant and reticulum and to stay permanently and in directcontact with the rumen liquid, reticulum liquid, or both the rumen andreticulum liquid, wherein the apparatus comprises at least: a) at leastone sensing unit for sensing a characteristic value of dissolved carbondioxide in the liquor of rumen, reticulum, or both rumen and reticulum;and b) at least one first communication unit for wireless communicationof data with a respective second communication unit outside theruminant, wherein the at least one sensing unit includes at least oneattenuated total reflectance (ATR) sensor, wherein the at least onesensing unit further comprises a light source emitting light, wherein alight channel is provided that leads light generated by the light sourceinto a prism of the at least one attenuated total reflectance sensor,said prism having a higher refractive index than rumen liquid, reticulumliquid, or both rumen and reticulum liquid, wherein the prism of the atleast one attenuated total reflectance sensor is capable of being indirect contact with the rumen liquid, reticulum liquid, or both rumenand reticulum liquid, and wherein the apparatus comprises a hermeticcasing that provides protection from an outside environment, wherein thehermetic casing is made at least in part from stainless steel with aspecific gravity greater than 2.3 g/cm³ to keep the apparatus on therumen and the reticulum liquid, wherein the at least one sensing unitfurther has the capacity of self-calibration and comprises a battery andan energy harvester used to increase battery lifetime by harvesting thesmall energy generated by rumen peristaltic movements and cattle motion.14. Apparatus according to claim 13, wherein the light source is an IRlight source.
 15. (canceled)
 16. Apparatus according to claim 5, whereinthe light source emits an infrared radiation with a wavelength of 4.27um.